1、Designation: C1722 11C1722 18Standard Guide forRepair and Restoration of Dimension Stone1This standard is issued under the fixed designation C1722; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last revision. A number
2、 in parentheses indicates the year of last reapproval. Asuperscript epsilon () indicates an editorial change since the last revision or reapproval.1. Scope1.1 This guide describes materials and procedures for restoring facades constructed of or finished with dimension stone. All ofthe materials, pro
3、cedures, and principles are suitable for restoration of historic and nonhistosric structures.1.2 This guide is not intended to address restoration of interior dimension stone, although many of the materials and proceduresmay be suitable for interior use.1.3 The values stated in inch-pound units are
4、to be regarded as standard. The values given in parentheses are mathematicalconversions to SI units that are provided for information only and are not considered standard.1.4 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibili
5、tyof the user of this standard to establish appropriate safety safety, health, and healthenvironmental practices and determine theapplicability of regulatory requirementslimitations prior to use.1.5 This international standard was developed in accordance with internationally recognized principles on
6、 standardizationestablished in the Decision on Principles for the Development of International Standards, Guides and Recommendations issuedby the World Trade Organization Technical Barriers to Trade (TBT) Committee.2. Referenced Documents2.1 ASTM Standards:2C5 Specification for Quicklime for Structu
7、ral PurposesC10 Specification for Natural CementC91 Specification for Masonry CementC119 Terminology Relating to Dimension StoneC141 Specification for Hydrated Hydraulic Lime for Structural PurposesC150 Specification for Portland CementC207 Specification for Hydrated Lime for Masonry PurposesC270 Sp
8、ecification for Mortar for Unit MasonryC1180 Terminology of Mortar and Grout for Unit MasonryC1242 Guide for Selection, Design, and Installation of Dimension Stone Attachment SystemsC1324 Test Method for Examination and Analysis of Hardened Masonry MortarC1329 Specification for Mortar CementC1489 Sp
9、ecification for Lime Putty for Structural PurposesC1515 Guide for Cleaning of Exterior Dimension Stone, Vertical And Horizontal Surfaces, New or ExistingC1521 Practice for Evaluating Adhesion of Installed Weatherproofing Sealant Joints2.2 OSHA Directive:STD 1-12.026 Abrasive Operations Using Cut Off
10、 Wheels and Masonry Saws3. Terminology3.1 DefinitionsFor definitions of terms used in this guide, other than those listed below, refer to Terminology C119 andTerminology C1180.1 This guide is under the jurisdiction ofASTM Committee C18 on Dimension Stone and is the direct responsibility of Subcommit
11、tee C18.07 on Environmental Properties,Behavior, and Cleaning.Current edition approved Oct. 1, 2011Nov. 1, 2018. Published November 2011November 2018. Originally approved in 2011. Last previous edition approved in 2011 asC172211. DOI: 10.1520/C1722-11.10.1520/C1722-18.2 For referencedASTM standards,
12、 visit theASTM website, www.astm.org, or contactASTM Customer Service at serviceastm.org. For Annual Book of ASTM Standardsvolume information, refer to the standards Document Summary page on the ASTM website.This document is not an ASTM standard and is intended only to provide the user of an ASTM st
13、andard an indication of what changes have been made to the previous version. Becauseit may not be technically possible to adequately depict all changes accurately, ASTM recommends that users consult prior editions as appropriate. In all cases only the current versionof the standard as published by A
14、STM is to be considered the official document.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States13.2 Definitions of Terms Specific to This Standard:3.2.1 defectnaturally occuring flaw in the stone.3.2.2 dimension stone restoration consul
15、tantone who is knowledgeable and experienced with the care, restoration, and repairof building dimension stone.3.2.3 distresslocalized damage of stone units such as cracks, chips, holes, deterioration, bowing, and projections that havebeen broken off or worn down caused by wear, erosion, settlement,
16、 displacement, or other adverse chemical or mechanical actions.3.2.4 dutchman repaira stone repair method whereby a portion of a stone unit is cut out and replaced with another piece ofstone (called a dutchman). The dutchman is usually rectangular or square in shape, but may also be rounded, and is
17、usually at acorner or edge of the stone unit.3.2.5 pointingplacing mortar in the outer portion of the joints between stone units. To point stone joints, the outer portion ofthe joints must either be left open during installation or cut or ground out, i.e. have the mortar removed from the outer porti
18、on ofthe joint. New mortar is then pressed into the joint with a pointing tool. The increased compaction of the new mortar provides animproved resistance to water penetration at the joint compared to the primary stone setting mortar.3.2.5.1 repointingthe removal of existing mortar from the outer por
19、tion of the joints between stone units and the subsequentpointing of the joints.3.2.5.2 tuck pointing (tuckpointing, tuck-pointing)this term is intentionally not used in this standard, because it is often usedinconsistently. It is variously used to mean repointing, simply pointing, or applying a rai
20、sed bead of mortar (often of a differentcolor) down the middle of mortar joints.3.2.6 proprietary repair mortaran exclusively manufactured product formulated from cementitious compounds, fineaggregates, mineral pigments, possibly bonding agents, and other additives. It is used for filling cracks, ho
21、les, and otherdepressions in stone units or for rebuilding the surface of damaged stone units to their original profile.3.2.7 repair mortar, cement-basedrepair mortar utilizing portland cement, masonry cement, blended cement, mortar cement,or natural cement as the primary binder.3.2.7.1 repair morta
22、r, polymer-modifiedcement-based repair mortar incorporating a dry or liquid polymer modifier as asecondary binder, to alter the performance properties3.2.7.2 repair mortar, polymer-basedrepair mortar consisting of a polymer binder and aggregates, without cement orhydraulic components.4. Significance
23、 and Use4.1 The purpose of this guide is to assist those who wish to restore facades constructed of or finished with dimension stone. Itis an aid to owners, building managers, architects, engineers, contractors and others involved with restoring dimension stone.4.2 This guide is not meant to superse
24、de manufacturers directions and recommendations for the use of their specific products,or written directions from the architect or building owner. When manufacturers directions are in conflict with this guide, followtheir recommendations or consult with their technical staff for further direction.4.
25、3 Prior to undertaking a full-scale repair or cleaning procedure, the methods under consideration for repair, patching orcleaning should be tested on an area not easily visible or on sample stones. The test will assist in judging the effectiveness of thechosen method and permit assessment of potenti
26、al damage to the building stone. Completely evaluate the success of the samplerepairs before undertaking the full-scale cleaning or repair procedure.5. Condition Survey and Restoration Plan5.1 The first step in a restoration project is to conduct a project survey consisting of a review of existing o
27、riginal architecturaldrawings and specifications and any original stone shop drawings that may be available. The stone shop drawings contain detailedinformation on stone and anchoring that is not always found in the architectural drawings. The shop drawing review is followedby a thorough examination
28、 of all exposed stone surfaces and related elements of the building envelope. Document distressed areasand existing repairs. Determine the causes of observed distress to avoid performing cosmetic repairs while failing to correct theunderlying problems. As an example, if problems result from water da
29、mage, the source of water penetration must be found andcorrected if the repairs are to be successful and long lasting. If the damage to the stone is a result of structural instability, thatstructural issue must be addressed before repairs are made.5.1.1 A dimension stone restoration consultant exper
30、ienced in natural stone facade design and construction should participatein the condition survey. If structural distress is observed, consult with a qualified engineer with stone facade design experience.For stone displaying deterioration with an unknown cause, a petrographer specializing in dimensi
31、on stone analysis can be consultedto determine whether a failure is related to inherent properties or mineralogical composition of the stone.5.1.2 During the condition survey, identify and document repairs performed during previous restorations. The condition ofexisting repairs should be assessed to
32、 determine if they are stable, if they have failed, if they are a potential threat to the buildingC1722 182fabric, or if they are posing a safety risk. Existing repairs can be made more apparent or can be damaged by cleaning or otherrestoration processes. The restoration consultant will be able to h
33、elp with the proper procedures concerning previous repairs.5.1.3 When necessary, appropriate field or laboratory testing, or both, is normally included with the condition survey to verifythe nature of existing materials and the extent of the work needed to restore the project to the desired conditio
34、n. Cleaningcompounds and repair materials under consideration should be evaluated and tested to confirm that they will be effective and willperform without detrimental effects to the stone for the life of the building.5.2 Once the condition survey is complete, prepare a restoration plan describing t
35、he repair and restoration work to be done.Perform the repairs and cleaning in a systematic, sequential order that will avoid damage to previously completed phases of theproject.5.2.1 Structural repairs must precede cosmetic repairs. For example, if expansion from rusting anchors is causing the stone
36、 tocrack, the anchors must be replaced or treated before repairing cracks.5.2.2 Perform testing of existing materials sufficiently in advance of restoration work to allow suitable cleaning, patching,repair, and replacement materials to be identified.5.2.3 When chemical cleaners are used, perform the
37、 cleaning before the patching. Some cleaning compounds adversely affectthe color and strength of the installed patch. Performing the cleaning first will help prevent damage or discoloration of the patchingmaterials and will also allow the patch materials to be matched to the cleaned surfaces of the
38、original material.5.2.4 If mortar in the joints is missing or deteriorated to the extent that water intrusion will occur, the joints must be repointedand allowed to cure before using a wet cleaning method. This is especially important if a water soak preparation or pressure waterspray cleaning metho
39、d is specified.5.2.5 Water repellents and clear sealers are sometimes inappropriately applied to limit water entry into stone. The applicationof a sealer will reduce the ability of the water that does enter the stone (from the bottom or back side) to evaporate from the exposedsurfaces. Limiting evap
40、oration can damage completed stone patches, accelerate surface loss in the form of chips, or causeexfoliation due to freezing of trapped water or accumulation of water-borne crystalline minerals within the body of the stone.Also,the patch material is likely to absorb the sealer at a different rate t
41、han the stone, which could make the patches more noticeable.Consult the sealer or water repellent manufacturer before the application to any stone to be sure the correct product is being usedfor a correct resolution of the problem.5.3 The National Historic Preservation Act allows qualifying historic
42、ally significant buildings or structures to be restored usingfederal funds set aside for historic preservation. The permitted type and extent of restoration work may be limited by governmentregulations.Aformalized Historic Structures Report is used in these cases to outline the propertys history, ex
43、isting condition, goalsfor the use of the property, and provides a recommended treatment approach and scope of work for restoration. The HistoricStructures Report is a multidisciplinary task and a team of several consultants consisting of historians, architects, engineers,materials scientists, and c
44、onservators is usually required to complete the report.6. Stone Patching6.1 Patching, GeneralPatching small areas of distress is commonly performed in order to avoid replacing full stone units.Thismay be preferable in certain situations to preserve as much of the historic fabric of the structure as
45、possible. However, areas ofdistress that do not impact the overall integrity of the stone unit and will not lead to further degradation of the stone, or do notdetract significantly from the stones appearance, are often left untreated.6.1.1 Patching compounds must properly adhere to and match the sto
46、ne as closely as possible, not only in appearance, but alsoin physical properties. Patching materials must be compatible with original stone.6.1.2 The original stone may be repaired with a patch, in lieu of replacement, because of historic value, a lack of availability,or difficulty replacing whole
47、pieces. For these reasons, it is very important that the original stone being repaired be carefullyprotected from further damage. The physical properties of patching compounds should be verified so the resulting performancecharacteristics of the patch do not conflict with the performance characteris
48、tics of the surrounding stone. It is generally agreed thatit is better for the patch (which can be easily replaced) to fail than to cause any further damage to the existing, historically valuable,irreplaceable, facade. In the following paragraphs, there are specific examples of physical properties a
49、nd how they affect theviability of the patch with a specific stone.6.1.3 The combined compressive strength and modulus of elasticity of the patching material should produce similar or lowerperformance characteristics to the analogous properties of the original stone for a non structural repair. Consult an experiencedstone restoration consultant to confirm that the combined properties of the patching material do not result in performancecharacteristics that could damage the particular stone for a specific project.6.1.4 Patching compounds should also have a comparabl
